Multioffice telephone system



A. J. RAY

IULTIOFFICE TELEPHONE SYSTEM Oct. 4, 1932.

Original Filed Sept. 23. 1922 4 Sheets-Sheet 1 Hfhur J. Haq 6&4. wz df En.:

Oct. 4,

1932. A, J, RAY 1,881,297

UULTIOFFICE TELEPHONE SYSTEM Original Filed Sept. 23. 1922 4 Sheets-Sheet 2 l l l l l l Od- 4, 1932- A. J. RAY 1,881,297 uum'xormc TELEPHoNE sisma Original Filed Sept. 23. 1922 4 Shee'ts-Sheet I5 -Imfamnr- Ehuf J. BEL' Oct. 4, 1932. A. J. RAY 1,881,297

IULTIOFFICE TELEPHONE SYSTEM Original Filed Sept.' 23, 1922 4 Sheets-Sheet 4 @6% WMSH:

Patented Oct. 4, 1932 UNITED STATES PATENT OFFICE .ARTHUR I. BAY, Ol' CHICAGO, ILLINOIS,

ASSOCIATED ELECTRIC LABORATORIES,

'non or DELAWARE IULTIOFFICE TELEPHONE SYSTEM Application led September 23, 1922, Serial No. 589,985. Renewed November 21, 1931.

The present invention relates to multi-of fice telephone systems in general, but is concerned more particularly with multi-oflice vtelephone systemsin which different types of equipment are used in the several oflices; and the principal object, briefly stated, is the production of new and improved circuit arran e- 4ments, whereby code impulses suitable or operating call indicators may be translated into impulses for operating step by step automatic switches. In its specific embodiment, the'present invention is employed in a multi-office net work -in which at least one of the oilices is a semiantomatic office in which machine switches are employed for establishing the connections; in which certain other of the oiices are manual oiices operated according to manual practice; and in which at least one other oiiice is an automatic oilice in which step by step switches are employed. In this mixed system as set above, the senders in the semi-automatic machine switching office are arranged to operate local switches according to a non-decimal system of notation as is the usual practice in machine switching systems. However, when a call originates in the machine switching oiice which is intended for an oilice of the system which is operated in some other manner, the sender must be arranged to send out the number to the other ottico on the decimal basis. Systems have been designed heretofore which send out coded impulses for operating call indicators in manual offices on the decimal basis. Accordingly, in order tohave the equipment uniform, it is desirable to produce suitable equipment whereby these coded impulses ma betranslated into impulses which are suita le for operating step by step switches.

The above mentioned and other features of the invention will appear in the accompanying drawings and description, together with the a pended claims.

Reiierring now to the dra-wings, Figs. 1 and 2 should be placed in order with the corresponding lines at the ends thereof in ali ment, and with Figs. 3 and 4 in order und-2r Fig. 2 with the corresponding interconnecting lines in alignment; and when so arranged,

show by means of the usual circuit diagrams `suflicient of the apparatus in a telephone sysimpulses, for decoding them, and for sending out the decoded impulses; and step by step automatic switches, such as D Fig. 2, which respond to the impulses sent out by the dccoder.

Figure 1 of the drawings shows a calling subscribers substation A and line, with brushes of an office selector at the semi-automatic operators position, which selector has access through two conductor trunks, such as the one extending through the trunk circuit TC, Fig. 2, to the Strowger selectors, such as the selector D, in the Strowger oiice. lVithin the small dotted rectangle at the left-hand side of Fi 1, there are shown the brushes of a cord nder switch which is operated to connect an idle sending device to a cord circuit which has been connected to the calling line. Within the large dotted rectangle at the right-hand side of Fig. 1, there are shown the operators key set and the registers for controlling the transmission of impulses which operate manual call indicators when the call is extended to a manual office or, after being translated, operate Strowger switches when the office selected is a step by step automatic oiiice. Within the dotted rectangle shown in the middle of Fig. 1, there is shown an impulse transmitting device which, under the control of the registers, transmits the various combinations of the coded impulses.

In this disclosure the showing of the apparatus and circuits for selecting the manual operators position has been abbreviated, but it may be of the character of the system disclosed in the patent to Lundell, No. 1,168,319, of January 18, 1916.

The office Selector referred to in the description may be of the type illustrated in the patent to Craft and Reynolds, No. 1,123,696, of January 5, 1915, although 1t w1 ll be readily understood that any automatlc selector switch can be employed in this system w1th out departing from the spirit of the invention.

In the description reference is made to sequence switches and registers. The structure of such se uence switches and registers as are shown in 4ig. 1 may be similar to that shown in the patent to Reynolds and Baldwin, No. 1,127,608, of February 9, 1915. I

In Fig. 2 there is shown a trunk circuit TC with which there is associated a secondary switch SS which has access to a plurality of decoders, one of which is shown in Figs. 3 and 4.

The selector D, Fig. 2, is an automatic switch of the usual vertical and rotary type, having sets of bank contacts arranged 1n ten horizontal rows or levels.

The secondary switch SS, Fig. 2, is mechanically of the well known rotar type, in which the wipers have no norma position and move in a forward direction only. The sender S and the sequence switch SE, Fig. 4 are mechanically identical with the secondary switch SS, Fig. 2.

Figure 5 is a table showing the code according to which the impulses, representing the digits of a number, are sent. It will be noted that there are light positive and negative, and heavy negative impulses. Each character contains two negative impulses, while only certain ones contain positive impulses. A casual examination reveals the fact that the last five characters are the same as the first five, respectively, with the exception that the second negative impulse is heavy instead of li ht.

gFigure 6 is a table showing how a set of setup relays, the set comprising relays 301-304, inclusive, Fig. 3, for example, responds to the various series of impulses. In this table X placed in a space means that the relay corresponding to that space is operated. A blank space indicates that the corresponding relay is not operated. Also, in this table the rows from left to right represent a set of relays, for example, relays 301-304, inclusive, respectively, Fig. 3. Comparing Fig. 6 with Fig. 5, it will be noted that the first relay in a set, taking them as numbered to Fig. 3, is operated for each positive impulse in the first column of the table shown in Fig. 5; the second relay is operated for each heavy negatiye impulse in the second column; the third relay is operated for each positive impulse in the third column; and the fourth relay is operated for each heavy negative impulse in the fourth column. From this it will be observed that no set-up relay is operated by a light negative impulse.

It is thought that the invention will be more clearly understood from the following detailed description of the method of establishing a connection of the calling substation A to a called substation whose line terminates in the step by step automatic oice.

conductors 51 and 52 to the calling line manually or by any other suitable means. When the semi-automatic operator connects the cord circuit to the calling line, a cord finder whose brushes are indicated at 58 and 59 operates to connect an idle sending device to thel cord circuit conductors in use.

When the semi-automatic operator connects the cord circuit to the calling line, she ascertains the number of the Wanted subscriber and proceeds to set this up on the keyboard of her sending device. Assuming that the oi'tice designatlon given is that of the automatic step by step oflice and that the subscribers number is 4567, the o rator depresses the ofice key (not showneand then depresses the corresponding thousands, huni dreds, tens and unlts keys in response to which the associated sequence switch registers are moved and come to rest in the corresponding positions. The thousands register 22 stops in position 4, the hundreds register 23 stops in position 5, the tens register 24 stops in position 6, and the units register 25 stops in position 7 Since no station has been designated, which is common practice for straight lines and for jack per station party lines in which the party lines, as well as the strai ht lines, have only four digits in their num rs, the operator operates the station key corresponding to the digit 0. Consequently, the station register 21 stops in position 0.

It may be stated further that it is necessary for the operator to depress a station key in order to cause the indicator lamps in the manual otlices to be operated correctly and also to allow the correct number to be set up on the decoders in the automatic office.

It will be assumed that the office selector whose brushes are indicated by the numerals 71 and 72, has been set in accordance with the oliice designation and has selected a trunk leading to the automatic office. It will be assumed also that the sequence switch associated with the ollice selector has been moved into position 11.

After the sending device has been set and when the olice selector has been operated to extend the calling line to the automatic ofice, the sequence switch associated with the cord finder moves into position 7, whereupon a circuit is established which moves sequence switch 61 out of position 1. This circuit may be traced as follows: From ound by way of contact 60 of the cord iider sequence switch, contact 62 of sequence switch 61, and

the magnet of sequence switch 61 to battery.

When sequence switch 61 reaches osition 2,

relay 65 is brid ed across the con uctors of the selected trun r extending to the automatic office at sequence switch contacts 66 and through brushes 58 and 59, contacts 55 and 57, and the brushes 71 and 72 of the office selector.

IO In the automatic oiiice, conductor 98 is connected with line relay 112 of the secondary switch SS associated with the trunk circuit TC by way of armature 107 of relay 102 and its resting contact and armature 104 and its resting contact, and conductor 99 is grounded by way of armature 110 of relay 102 and its resting contact, and armature 105 and its resting contact. Consequently, relay 112 of the secondary switch SS and relay 65 associated with the sequence switch 61 energize in series. Relay 65, upon energizing closes a circuit to move sequence switch 61 out of osition 2 and into position 3, at armature 3 and its working contact, by way of contact 64.

Relay 112 Fig. 2, upon energizing, closes a circuit for switching relay 111 and stepping magnet 113 in series at armature 116, and at armature 117 connects test wiper 121 to the junction of stepping magnet 113 and switching relay 111. In case the decoder trunk upon which the wipers 118-123, inclusive, are standing is idle, the operation of armature 117 has no particular effect and switching relay 111 energizes immediately. Assuming, however, that the trunk upon which the wipers are standing is busy, switching relay 111, being short circuited by the ground potential which is present on the test contact thereof, does not energize and the wipers 118-123, inclusive, are advanced step by step in search of an idle trunk by the buzzer-like action of stepping magnet 113, which operates from gro-und on the busy test contacts. When an idle trunk is reached, which trunk it will be assumed is the one comprising conductors 124429, inclusive, switching relay 111, being no longer short circuited, energizes in series with stepping magnet 113, stepping magnet 113 not energizing on account of the high resistance of switching relay 111. Upon energizing, switching relay 111 opens the test circuit and prepares the holding circuit at arnlature 115, thereby grounding test wiper 121 and making the seized trunk busy immediately. As a further result of the energization of switching relay 111, it connects relay 102 with wiper 120 at armature 114. When this occurs, relay 102 and relay 321, Fig. 4, energize in series over the following circuit: From ground, by way of relay 102, armature 114 and its working contact, wiper 120, conductor 126, relay 321, Fig. 4, and resistance 381 to battery.

Relay 321, upon energizing, places ground on conductor 201 at armature 344 in series with the resting contact of armature 348 and said armature. This ground potential extends to release trunk conductor 127 by way of armature 274 of relay 271, Fig. 3, and its resting contact, thereby establishing the usual holding circuit for switching relay 111 of the secondary switch SS, Fig. 2. As a further result of the energization of relay 321, it places ground on conductor 202 at armature 343, thereby pre aring a locking circuit for various relays in ig. 3. As a still further result of the energizaticn of relay 321, it closes at armature 345 a circuit for relay 365 by way of the resting contact of armature 383 and said armature. Relay 365, upon energizing, places ground on wiper 368 at armature 388; disconnects ground from the contacts of wiper 369 at armature 387 disconnects stepping magnet 328 of the sender S from wiper 340 at armature 384; and at armatures 385 and 386 disconnects relay 364.

Relay 102 of the trunk circuit TC, Fig. 2, upon energizing in series with relay 321, Fig. 4, extends the line conductors of the selector D to wipers 118 and 119 of the secondary Y switch SS at armatures 108 and 109, whereupon line relay 135 of the selector D energizes over conductors 124 and 125 which are normally connected together at armatures 350 and 353 of relays 324 and 325, Fig. 4, and their resting contacts. Upon energizing, line relay 135 closes a circuit for release relay 136 at armature 146. Release relay Y136, upon energizing, opens a point in the circuit of release magnet 142 at armature 148 and prepares a circuit for vertical magnet 140, and at armature 147 places ground upon the associated release trunk conductor, thereby closing a circuit for release relay 101. Relay 101 energizes but does not produce any result at this time. As a further result of the ener gizaton of relay 102, it disconnects conductors 98 and 99 from the winding of line relay 112 of the secondary switch SS and ground, respectively, and armatures 107 and 110, and extends them by way of wipers 122 and 123, conductors 128 and 129, and armatures 275 and 276 and their resting contacts, to relays 210-212, inclusive.

In the originating oiice, relay 65, Fig. 1. deenergizes in response to the operation of relay 102, Fig. 2, and at armature 73 and its resting contact closes a circuit through contact 63 for the magnet of sequence switch 61. whereupon sequence switch 61 moves out of position 3 and through its various operating positions back to position 1, during which a complete set of code impulses is transmitted to relays 210, 211, and 212, Fig. 3, relay 65 being disconnected from in bridge of wipers 58 and 59 at contact 66 when sequence switch 61 moves out of position 3.

In this descri tion it will be assumed that the impulse which is transmitted from battery through the full numbered positions of sequence switch 61 to the automatic oiiice by way of conductor` 98 and back on conductor 99 to ground are positive, and that the impulses which are transmitted to the automatic olice through the fractionally numbered positions of sequence switch 61 over conductor 99 to the automatic office and back over conductor 98 to ground are negative..

Since the station register 21 is in positlon 0, no impulse is sent in position 4 of sequence switch 61. In position41/2 of sequence switch 61, however, a light negative impulse is sent over the following circuit: From grounded battery by way of resistance 76, contact 77 of register 21, contact 78 of sequence switch 61, contact 69 of sequence switch 61, brush 59, sequenceswitch contact 57, brush 71, conductor 98, and thence by way of a previously traced circuit to and throug relays 21.0-212, inclusive, Fig. 3, back over conductor 99, brush 72, sequence switch contact 55, brush 58, and contact 68 of sequence switch 61 to ground.

Se uence switch 61 passes through position 5 wit out sending an impulse. In position 51/2, a second light negative impulse is sent over the following circuit: From battery by way of resistance 76, contact 79 of register 21, contact 80 of se uence switch 61, contact 69, brush 59, prevlously traced circuit to brush 58, and contact 68 to ground.

Since the thousands register 22 is in position 4, no impulse is sent when sequence switch 61 is in position 6. In position 6%, however, a light negative impulse is sent over the following circuit: From battery, by way of resistance 76, contact 80 of register 22, contact 84 of the sequence switch 61, contact 69, and thence by way of the previously traced circuit to ground by way of contact 68.

In position 7, a light positive im ulse is sent over the following circuit: From attery, by way of resistance 76, contact 81 of register 22, contact 83 of sequence switch 21, contact 67 of sequence switch 21, brush 58, thence to relays 210-212, inclusive, by way of the lower` conductor 99, back by way of conductor 98 to brush 59, and thence to ground by way of contact of sequence switch 61.

In position 7% of sequence switch 61, a light negative impulse is transmitted as follows: From battery, by way of resistance 76, contact 82 of sequence register 22, contact 85 of sequence switch 61, and thence to ground by way of the previously traced circuit.

Since the hundreds register 23 is in position 5, a light negative impulse is sent when sequence switch 61 reaches position 81/2, the circuit being as follows: From battery, by way of resistance 76, contact 86 of register 23, contact 88 of sequence switch 61, and

'thence by way of the previously traced circuit to ground.

In position 91/2 of sequence switch 61, a heavy negative impulse is transmitted by way of the followin circuit: From battery, by way of contact 8 of register 23, contact 89 of sequence switch 61, and thence to ground by way of the previously traced circuit.

Since register 24 is in position 6, a light positive impulse is delivered when sequence switch 61 moves into position 10, the circuit being as follows: From battery, by way of resistance 7 6, contact 90 of register 24, contact 92 of sequence switch 61, contact 67 of sequence switch 61, and thence to ground by waly of the previously traced circuit.

n position 10%, a li ht negative impulse is delivered as follows From battery, by way of resistance 7 6, contact 91 of register 24, contact 93 of sequence switch 61, and thence to ground by way of the previously traced circuit.

In position 111/2 of sequence switch 61, a

heavy negative impulse is delivered as follows: From battery, by way of contact 94 of register 24, contact 95 of sequence switch 61, and thence to ground by way of the previously traced circuit.

Since the units register 25 is in position 7, a heavy negative impulse is transmitted when sequence switch 61 reaches position 121/2, the circuit being as follows: From battery, by way of contact 96 of register 25, contact 31 of sequence switch 61, and thence to ground by way of the previously traced circuit.

In position 13% of sequence switch 61, another heavy ne ative impulse -is transmitted as follows: rom battery, by way of contact 97 of register 25, contact 32 of sequence switch 61, and thence to ground by waly of the previously traced circuit.

fter the impulse transmitting sequence switch 61 has passed out of position 131/2 and before it completes its operation and returns to position 1, the cord finder Whose brushes are designated by the characters 58 and 59, as well as the associated sequence switch, is started on its way to its normal position. At the same time, the sequence switch, contacts of which are shown associated with the trunk selecting switch, is moved out of position 11 to open the contacts 55 and 57 and to close the contacts 54 and 56, thereby bridging the calling line across conductors 98 and 99.

In the automatic oiiice, relay 210, Fig. 3, upon responding to the first light negative impulse in the station digit 0, which impulse does not operate relay 211 on account of the way it is poled nor relay 212 on account of its marginal adjustment, closes a circuit from the grounded conductor 202 for relay 214 and 213 1n series at armature 215, by wa of armature 218 and its resting contact. elay 214 energizes over this circuit, but relay 213 does not energize on account of its marginal adjustment` Upon energizing, relay 214 locks itself to conductor 202 at armature 221, through the right-hand winding of relay 213. Relay 213 docs not energize at this time, however, owing to the fact that its righthand winding is short circuited. As a further result of the energization of relay 214, it disconnects armature 216 of relay 211 from armature 253 and connects it to armature 256 at armature 222, and at armature 223 closes a circuit for relay 30 by way of armature 235 and its resting contact. Relay 230, upon energizing, connects up armature 255 at armature 253; places a multiple ground on conductor 201 at armature 241; and at armature 252 closes a' locking circuit for itself in series with relay 225. Relay 225;,does not energize at this time, however, for the reason that it is short circuited. Relay 210, upon deenergizing when the first negative impulse subsides, opens the initial circuit of relay 214, whereupon relay 213 energizes in series with relay 214 on account of the fact that current is ilowing through its two windings in series; disconnects arma-ture 215 from the right-hand terminal of relay'214 and connccts it to the left-hand terminal thereof at armature 218; places a shunt around armature 223 and its working contact at armature 220; and at armature 219 disconnects armature 217 of relay 212 from armature 236 and connects it to armature 237.

"When the second light negative impulse is transmitted, relay 210 energizes again and short circuits relay 214 at armature 215, whereupon relay 214 deenergizes but does not produce any apparent result at this time. lVhen relay 210 deenergizes at the end of the impulse, it opens the circuit of relay 213 at armature 215, whereupon relay 213 deenergizes and removes the shunt from around relay 225 at armature /220,whereupon relay 225 energizes in series with relay 230 and extends the operating conductors which it controls to the armatures of relay 226 at armatures 235-237, inclusive.

From the above, it will be seen that the effect of the sending of the station digit 0 is merely to prepare the circuits for the reception of the thousa-nds digit 4.

Then the first light negative impulse in the thousands digit 4 is transmitted, relay 210 is operated and closes a circuit for relay 214 in series with the lefthand winding of the marginal relay 213. Relay 214, upon energizing, closes the above-mentioned locking circuit for itself which includes the righthand winding of relay 213 at armature 221; disconnects armature 216 of relay 211 from armature 255 and connects it to armature -256 at armature 222; and at armature 223 closes a circuit for relay 231 by way of armature 235 and its working contact and armature 238 and its resting contact. Relay 231, upon energizing, closes the usual locking circuit for itself in series with relay 226 at armature 254; connects up armature 259 at armature 256; and at armature 255 shifts the operating circuit controlled thereby from relay 301 to armature 258 of relay 232.

Vhen relay 210 deenergizes at the end of the impulse, it opens the initial circuitvof relay 214, whereupon relay 213 energizes in series with relay 214; with results which are apparent from the foregoing description.

When the succeeding light positive impulse is transmitted, relay 211 energizes and closes a circuit for the third thousands relay 303 as follows: From ground, by way of conductor 202, working contact of armature 216 and said armature, armature 222 and its working Contact, armature 256 and its working contact, armature 259 and its resting contact, and the right-hand winding of relay 303 to battery. Relay 303, upon energizing, closes a locking circuit for itself at its inner armature.

When the second light negative impulse in the thousands digit 4 is transmitted, relay 210 energizes and short circuits relay 214, whereupon relay 214 deenergizes. At the end of the impulse, relay 210 deenergizes and opens the circuit of relay 213. Relay y213, u on deenergizing,opens the initial circuit of re ay 231 at armature 220, whereupon relay 226 energizes in series with relay 231, by way of armature 254 and its working contact, thereby extending the circuits controlled by relay 226 at armatures 23S-240, inclusive, to the corresponding armatures of relay 227.

When the light negative impulse of the hundreds digit 5 is transmitted, relay 210 energizes again and closes a circuit for relay 214, whereupon relay 214 energizes also, and closes a circuit for relay 232 which extends from ground as previously traced to armature 238 and thence by way of the working contact thereof, armature 242 and its resting contact, and relay 232 to battery. Relay 232, upon energizing, closes the usual locking circuit for itself through relay 227 at arma,- ture 257.

When the light negative impulse subsides relay 210 deenergizes and opens the initial circuit of relay 214, whereupon relay 213 energizes in series with relay 214 with results that are apparent.

The next and last impulse in the hundreds digit 5 is a heavy negative impulse. Consequently, the negative relay 210 and marginal relay 212 are both energized. Relay 210, upon energizing, short circuits relay 214, whereupon relay 214 deenergizes. Relay 212, upon energizing, closes a circuit for the fourth hundreds relay 308 as follows: From ground, by way of conductor 202, working contact of armature 217 and said armature, armature 219 and its working contact, armature A237 and its working contact, .armature 240 andits working contact, armature 244 and its resting contact, and the right-hand winding of re ay 308 to battery. Relay 308, upon energizing, closes a locking circuit for itself atits inner armature.

At the end ofthe heavy negativeimpulse, relays 210 and 212 deenergize and relay 210 opens the circuit of relay 213, whereupon relay 213 also deenergizes and removes the Ashunt from around relay 227 at armature 220. When this occurs, relay 227 energizes through amature 257 and its workin contact, and transfers the circuits controlle at armatures 242-244, inclusive, to the corresponding armatures of rela 228.

The first impulse in the tens di 't 6 is a positive impulse. When this impu se is sent, relay 211 energizes and closes a circuit for the first tens relay 309 as follows: From ground, by way of conductor 202, working contact of armature 216 and said armature, armature 222 and its resting contact, armature 253 and its working contact, armature 255 and its working contact, armature 258 and its working contact, armature 261 and its resting contact, and the right-hand winding of relay 309 to battery. Relay 309, upon energizing, closes a locking circuit for itself at its innerl armature. I

When the light negative impulse of the tens digit 6 is sent, relay 210 energizes and closes a circuit for relay 214. Relay 214, upon energizing, closes at armature 223 a circuit for relay 233 which extends as previously traced to armature 242, and thence by way of the workingv contact thereof, armature 245 and its resting contact, and relay 233 to battery. Relay 233, upon energizing, shifts the two lower operating circuits at armatures 261 and 262 and at armature 260 closes the usual loclring circuit for itself in series with relay 228.

When the impulse subsides, relay 210, upon deenergizing, opens the initial circuit or relay 214, whereupon relay 213 energizes in series with relay 214 with results that are readily apparent.

When the heavy negative impluse in the tens digit `6 comes in, relays 210 and 212 are energized. The energization of relay 210 results in the deenergization of relay 214 in the hereinbefore described manner. The energization of relay 212 results in a circuit being closed for the fourth tens relay 312, which circuit extends as previously traced to armature 244, and thence by way of the working contact thereof, armature 247 and its resting contact, and the right-hand winding of relay 312 to battery. Relay 312, upon energizing, closes a locking circuit for itself at its inner armature.

When the impulse subsides, relays 210 and 212 deenergize, whereupon relay 213 deenergizes in response to the opening of its circuit at armature 215 of relay 210. Upon deenergizing, relay 213 removes the shunt from around relay 228 whereupon relay 228 ener izes with results that are apparent from the oregoing description.

When the first heavy negative impulse of the units digit 7 comes in, relays 210 and 212 are energized.v As a result of the energization of relay 210, relay 214 energizes and closes a circuit for relay 234. Relay 234, upon energizing, shifts 4the two lower operating conductors at armatures 264 and 265, and at armature 263 closes a locking circuit fori itself in series with relay 229. Relay 212, u on energizing, closes a circuit for the secon units relay 314 as follows: From ground, by way of conductor 202, working contact of armature 217 and said armature, armature 219 and its resting contact, armature 236 and its working contact, armature 239 and its working contact, armature 243 and its working contact, armature 246 and its working contact, armature 249 and its restin contact, and the ri ht-hand winding of reay 314 to battery. elay 314 upon energizing, closes a locking circuit for itself at its inner armature.

When the impulse subsides, relays 210 and 212 deenergize and relay 213 energizes as a result of the deenergization of relay 210.

When the second heavy negative impulse in the units di it 7 is transmitted, relays 210 and 212 energlzeas before. As a result of the energization of relay 210, relay 214, being short circuited, de-energizes. As a result of the energization of rela 212, a circuit is closed for relay 316 which extends as previously traced to armature 247, and thencel by way of the working contact thereof, armature 250 and its resting contact, and the'righthand winding of relay 316 to battery. Relay 316, upon energizing, closes a locking circuit for itself at its inner armature.

When the impulse subsides, relays 210 and 212 deenergize, and relay 213 deenergizes in response to the deenergization of relay 215. Upon deenergizing, relay 213 removes the shunt from around relay 229 at armature 220, whereupon relay 229 energizes and disconnects the three upper operating leads at armatures 248-250, inclusive, and at armature 251 closes a circuit for relay 272. Relay 272, upon energizing, disconnects conductors 128 and 129 from rela s 210-212, inclusive, and extends them to t e windings 'of relay 273 at armatures 275 and 276.

When the calling line has been bridged across conductors 98 and 99 at contacts 54 and 56, Fig. 1, as pointed out hereinbefore, relay 273 energizes over the calling line; places a multiple ground on release trunk conductor 127 at armature 278; and at armature 277 closes a circuit for relay 271. Relay 271, upon energizing, separates conductors 127 and 201 at armature 274, leaving series of impulses Srgrsiductor 127 grounded only at arnature The operation of the sending mechanism of the decoder will be taken up now. It will be remembered that relay 365, Fig. 4, u on energizing in response to the closure o its circuit by relay 321 at armature 345, upon the seizure of the decoder, placed ground upon wiper 368 of the sequence switch SE at armature 388. When ground is placed on wiper 368, relay 324 of the sender S starts to vibrate, its circuit being as follows: From ground, by wa of the working contact of armature 345 o relay 321 and said armature, resting contact of armature 383 and said armature, armature 388 and its working contact, armature 378 and its resting contact, armature 374 and its resting contact, armature 357 and its resting cont-act, sending relay 324, and the constantly operating interrupter 359 to battery. Upon the first energization of relay 224, it separates conductors 124 and 125 at armature 350, leaving said conductors 124 and 125 joined together through armature 353 and its resting contact, and at armature 349 closes a circuit for stepping magnet 328 of the sender S. Stepping magnet 328, thereupon energizes, but, since the sender S is mechanically of the type of switch in which the wipers are advanced on the back stroke of thestepping magnet, the wipers are not moved and the pawl of the armature of magnet 328 merely engages another notch on the wiper driving ratchet wheel. When relay 324 deenergizes, it opens the circuit of stepping magnet 328 at armature 349, whereupon the wipers 329-332, inclusive, are advanced into engagement with the first set of bank contacts. Wiper 330, upon coming into engagement with the first associated bank contact, closes a circuit for relay 322,

from ground on the first contact, and through armature 347 and its resting contact. Relay 322, upon energizing, closes a locking circuit for itself in series with relay 323 at armature 333. Relay 323, however, does not energize at this time on account of the fact that it is grounded at both terminals.

Wipers 329-332, inclusive, continue to be advanced in the above manner step by step without producing any particular result until wiper 330 passes oli' the last bank contact. When this occurs, the initial circuit of relay 322 is opened, whereupon relay 323 energizes in series with relay 322; places ground on wiper 329 at armature 346 by way of armature 355 and its resting contact; and at armature 348 removes ground from conductor 201, leaving conductor 201 grounded through armature 241 of relay 230 and its working contact by the grounded conductor 202, which conductor is grounded at armature 243 and its working contact of relay 321. This operation occurs after the first have been received from the panel oice, but before the last series of impulses have been received. It may be here stated that the principal reason for the preliminary rotation of the sender wipers as above described is to afford an easy and cfficient means for releasing the decoder in case no impulses are Areceived from the machine switching ofiice within the prescribed time limit. This naturally follows at the end of the rotation of the sender wipers, when ground is removed from release trunk conductor 127 by relay 323, if relay 230, Fig. 3, has not been energized to ground conductor 127 at that point.

As a further result of the energization of relay 323, itprepares a circuit for relay 326 at armature 348, and at armature 347 disconnects wiper 330 from relay 322 and connects it to relay 325. Upon the next step -of wipers 329-332, inclusive, wiper 330 engages a grounded contact, whereupon relay 325 is' energized in series with armature 347 and its working contact;removes the shunt from around armature 350 and its resting contact at armature 353; prepares a locking circuit for relay 326 at armature 352; and at armature 351 closes a circuit for stepping magnet 366 of the sequence switch SE, from ground through the resting contact of armature 355 and said armature. Magnet 366, upon energizing, advances the associated pawl into engagement with the next notch on the associated ratchet wheel, but does not move the wipers of the sequence switch. Upon the next energization of sending relay.324, the usual circuit is closed for stepping magnet 328 at armature 349, and conductors 124 and 125 are separated at armature 350, thereby opening the circuit of line relay 135 of the selector D, Fig. 2. When relay 324 deenergizes, it closes the circuit of line relay 135 of the `selector D again at armature 350, and at armature 349 opens the circuit of stepping magnet 328, whereupon the wipers 329-332, inclusive, are advanced into engagement with the second set of bank contacts.

The operation continues as above described until the wipers 329-332, inclusive, are advanced into engagement with the fifth set of bank contacts, at which time the circuit of the line relay of the selector D has been opened four times. When the wipers of the sender S is in engagement with the fifth set of bank contacts, the following circuit is closed for the upper winding of test relay 327. From ground ,by way of wiper 368 of the sequence switch SE, the first associated bank contact, conductor 287, resting contact of the outer armature of relay 304 and said armature, outer armature of relay 301 and its resting contact, outer armature of relay 302 and its resting contact, outer armature of relay 303 and its working contact, conductor 284, the fifth Contact in the bank of wiper 331, wi ers 331 and 332, the fifth contact in the ank of wiper 332, and the upper winding of test relay 327 to battery. Test relay 327, upon energizing, completes the circuit of stop relay 326 at armature 358. Relay 326, upon energizing, opens the circuit of sending rela 324 at armature 357, while relay 324 is sti l in a deenergized condition; completes a lockin circuit for itself at armature 356; o ens t e circuit of ste ping magnet 366 o the sequence switch S at armature 355, whereupon magnet 366 deenergizes and advances the wi ers 367-369 inclusive, into engavement vwit the second set of associated bank contacts; and at armature 354 connects steppin magnet 328 to wiper 330 through the loca interru ter contacts of stepping magnet 328. hen this occurs, wipers 329-332, inclusive, are ra idly spun around to normal position by the uzzer-like action of stepping magnet 328, which magnet operates from ground on the contacts in the bank of wiper 330.

When the wipers of the sender S reach normal position, the local stepping circuit pf stepping magnet 328, together with the circuit of relay 325, is opened by the wiper 330 passing oil'` the last grounded contact, whereupon the wipers stop rotating. SloW` acting relay 325, upon deenergizing, opens a point in the circuit of stepping magnet 366 of the sequence switch SE at armature 351; replaces the shunt around armature 350 and its resting contact at armature 353; and at -armature 352 opens the locking circuit of relay 326. Slow acting relay 326, upon deenergizing, disconnects stepping magnet 328 from wiper 330 at armature 354; opens a point in its locking circuit at armature 356; prepares a circuit for magnet 366 at armature 355; and at armature 357 connects up sending relay 324 again, whereupon the wipers 329-332, inclusive, are started around again and the second digit in the number is sent out.

It may be pointed out that relays 325 and 326 are made slow acting so as to allow a suiiicient time to elapse between the sending of digits for the changeover and the trunk hunting operations of the automatic switches to take place.

Referring now to the selector D, Fig. 2, the effect of the sending out of the first digit 4 in the desired number will be taken up in detail. Each time line relay 135 deenergizes in response to one of the four interruptions produced in its circuit at armature 350 of sending relay 324, Fig. 4, as described above, it closes a circuit for vertical magnet 140 at armature 146, by way of armature 148 and its working contact, and slow acting series relay 137. By the operation of vertical magnet 140 the wipers of the selector D are raised step by step until they stand opposite the fourth level of bank contacts. Slow acting series relay 137 is maintained ener ized in series with vertical magnet 140 throng out the vertical movement and, in conjunction with of normal contacts 143, which close upon the lirst vertical step, closes a circuit for stepping relay 138 in series contacts 144 of rotary magnet 141. Stepping relay 138, upon energizing, prepares a circuit for rotary magnet 141 at armature 151, and at armature 150 closes a locking circuit for itself. At the end of the vertical movement, series relay 137 deenergizes and completes the circuit of rotary magnet 141 aty armature 149, whereypon rotary magnet 141 energizes and advances the wi ers 156-158, inclusive, into engagement wit the first set of bank contacts in the fourth level. Near the end of its stroke, rotar magnet 141 opens the circuit of stepping re ay 138, whereupon stepping relay 138 deenergizes and opens the circuit of rotary magnet 141 at armature 151. Rotary magnet 141, upon deenergizing, closes its interrupter contacts 144 a ain.

From this point the operation depends upon whether the trunk terminating 1n the first setof bank contacts is busy or Idle. If it is idle, switching relay 139 energizes immediately. If it is busy, switching relay 139, being short circuited by the ground potential found on the test contact thereof by test wiper 157 and transmitted to the junction of switching relay 139 and stepping relay 138 through armature 153 and its resting contact, does not energize and stepping relay 138 energizes, whereupon the switch wipers are advanced into engagement with the next set of bank contacts.

This alternate operation of stepping relay. 138 and rotary magnet 141 continues until an idle trunk is reached, which trunk it will be assumed is the one comprising conductors 162-164, inclusive. When said idle trunk is reached, switching relay 139, being no longer short circuited, energizes in series with stepping relay 138, stepping relay 138 not energizing on account of the high resistance of switching relay 139. Switching relay 139, upon energizing, opens the test circuit and prepares the holding circuit at armature 153; disconnects ground from armature 146 of line relay 135 at armature 154, thereby opening the circuit of release relay 136; and at armatures 152 and 155 disconnects the line conductors of the selector n from the windings of line relay 135 and extends them by way of wipers 156 and 158, bank contacts 159 and 161, and trunk conductors 162-164, inclusive, to the line relay of the selector to which the seized trunk extends. When this occurs, the lineA and release relays (not shown) of the said selector energize, and the latter places ground on release trunk conductor 163, thereby establishing the usual holding circuit for switching relay 139 and with interrupter l rela 101 before slow acting release rela'y186*- the hereinbefore described manner after the' end of the set time interval which terminated upon the falling back of stop relay 326 as pointed out above, and the interruptions are sent out by sending relay 324 at armature 350, after pick-up relay 325 has energized in response to wiper 330 comin into engagement with the first associate bank contact. In this case, the advance of the switch wipers and the sending out of interruptions continues undisturbed until the wipers of the sender are advanced into engagement with the sixth set of bank contacts, at which time five interruptions have been produced in the operating circuit at armature 350 by sending relay 324. With the wipers of the sender in engagement with the sixth set of bank contacts, a circuit is closed for the lower winding of test relay 327 as follows: From battery by way of wiper 367, the second associated bank contact, conductor 288, working contact of the outer armature of relay 308 and said armature, outer armatures and resting contacts of relays 305, 306, and 307, conductor 285, sixth contact in the bank of wiper 331, wi ers 331 and 332, sixth contact in the bank ofwiper 332, and the lower winding of relay 327 to ground. In response to the energization of test relay 327, the Wipers of the sequence switch are advanced into engagement with the next set of .bank contacts and the wipers of the sender are spun around to normal in the hereinbefore described manner.

In response to the sending out of the hun dreds digit 5 in the desired number, the hundreds selector to which the connection has been extended raises its wipers to the fifth level and picks out an idle connector in the usual manner.

When the wipers of the sender start around to bring about the sending out of the tens digit 6, they are rotated under the control of sending relay 324 as described above, until they reach the seventh set of contacts, at which time sending relay 324 has produced six interruptions in the operating circuit at armature 350. With the wipers of the sender in engagement with the seventh set of bank contacts, the following circuit for the lower winding of test relay 327 is closed From battery by way of wiper 367 of the sequence switch SE, the third associated bank contact,

conductor 290, working contact of the outer armature of relay 312, outer armature of relay 309 and its working contact, middle armature of relay 310 and its resting contact, cgnductor 281, seventh contact in the bank of wiper 331, wipers 331 and 332, seventh contact in the bank of Wiper 332, and the lower Winding of relay 327 to ground. The tens digit 6 is terminated in the usual manner,

upon the energization ofurelay 327, and the wipers of the sequence switch are advanced lnto engagement with the fourth set of bank contacts.

In response to the tens digit 6, the coni nector in use raises its wi pers to the sixth level of bank contacts inthe well-known manner.

As the units di 't 7 is being sent out, the wipers of the sen er are advanced step by step under the control of sending relay 324 until the eighth set of bank contacts is reached, at which time seven interru tions in lthe operatfng circuit have been pr uced.

With the wipers of the sender in engagement I with the eighth set of bank contacts, a circuit is closed for the lower winding of test relay 327 as follows: From battery by way of wiper 367 of' the sequence switch SE,

fourth associated bank contact, conductor 292, working contact of the outer armature of relay 316 and said armature, outer armature of relay 313 and its resting contact, outer armature of relay 314 and its working contact, conductor 282, the eighth contact in the bank of wiper 331, wipers 331 and 332, eighth contact in the bank of wiper 332, and the lower winding of test relay 327 to ound. Upon the energization of relay 327, t e units digit is terminated in the usual manner; the wipers of the sender S arespun around to normal; and the wipers of the sequence switch SE are advanced into engagement with the next and fifth set of bank contacts.

Wiper 368, upon coming into engagement with the fifth associated bank contact, closes a circuit for relay 363. Relay 363, upon energizing, closes a locking circuit for itself at armature 379; opens another point in the circuit of sending relay 324 at armature 378 so as to prevent the sender S from attempting to rend out another digit; and at armature 380 places ground on the junction of relay 321 and resistance 381, thereby short circuiting relays 321 and 102. Since relays 321 and 102 are short circuited, there is a. tendency for them to be slow to release, this action being Well known. Relay 321 has a comparatively weak adjustment and retains its armature attracted for an interval. Relay 102, Fig. 1, however, has a still spring adjustment an consequently, releases its armature almost immediately, regardless of the fact that it is short circuited. Upon deenergizing, relay 102 extends conductors 98 and 99 to the corresponding conductors of the selector D by way of armatures 103 and 106 at the normally closed contacts controlled b armatures 108 and 109, at the same time isconnecting the line conductors of the selector D from wlpers 118 and 119 of the secondary switch SS. This leaves the established connection under the control of the calling subscriber. As a further result of the deenergization of relay 102, it disconnects conductors 98 and 99 from wi ers 122 and 123 of the secondary switch SS) at 05 out as explained above,

armatures 107 and 110, themb circuit of relay 273, Fig. 3,v o the decoder. Relay 273, upon deenergizing, opens the circuit of relay 271 at armature 277. Relay 271, being slow acting, retains its armature attracted for an interval. As a further result of the deenergization of relay 273, 1t removes ground from release trunk conductor 127 at amature 278, whereupon switching relay 1.11 of the secondary switch SS deenergizes; disconnects itself from conductor 127 at armature 115; and at armature 114 disconnects relay 102 from relay 321, Fig. 4. The trunk circuit TC is now entirely separated from the decoder.

In the decoder, relay 271 deenergizes after an interval, but does not 1produce an particular result at this time. elay 321, ig. 4, deenergizes in response to being disconnected from relay 102 by switching relay 1 11 of the secondary switch SS, Fig. 2, as pointed o ut above, for the reason that it is then short circuited no longer. Upon deenergizing, relay 321 removes ground from conductor 202 at armature 343, whereupon relays 322 and 323, together with the various locked up relays shown in Fig. 3, deenergize. As a further result of the deenergization of relay 321, it opens the circuit of relays 363 and 365 of the sequence switch SE at armature 345, whereopening the upon relays 363 and 365 deenergize. Relay d 365, upon deenergizing, places ground upon all of the contacts in the bank of wiper 369, with the exception of the first contact, whereupon the wipers 367-369, inclusive, are advanced to normal position by the buzzer-like action of stepping magnet 366. It will be ,noted that the lower wlnding of relay 364 is in multiple with steppin magnet 366 during thetime that the wipers o the sequence switch are being rotated to normal. Consequently,

relay 364 is energized at this time and mainb tains release trunk conductor 127 grounded at armature 382, so as to prevent the decoder from being seized before the sequence switch SE reaches normal position. It will be noted also that the upper winding of relay 364 is connected to wiper 330 of the sender S. Consequently, relay 364 is maintained energized by its upper winding until the wipers of the sender have reached normal position in case they have not reached normal position, which is hkely to be the case if the calling subscriber hangs up while the sender S is oil normal. It will be noted that a circuit is provided through armature 384 and its resting contact for restoring the wipers of the sender to normal independent of armature 354 of relay 326 in case the calling subscriber hangs up and forces the release of the decoder while the sender is sending out a digit. The decoder is now in readiness to decode and transmit another number.

In response to the units the connector to digit 7 being sent d1 which the connection has been extended rotates its wipers into engagement with the seventh set of bank contacts in the chosen level, after which it signals the desired subscriber in the well known manner.

At the close of the conversation, when the calling subscriber hangs u his receiver, the circuit of the line relay ci) the connector to which the connection is extended is opened, whereupon the connector is released 1n the usual manner, ground being removed from release trunk conductor 163, Fig. 2, at the same time. When this occurs, relay 101 of the trunk circuit TC and switching relay 139 of the selector D deenergize. Switching relay 139, upon deenergizing, closes the usual circuit for release magnet 142, whereupon the wipers of the selector D are restored to normal position in the usual manner, and the circuit of release magnet 142 is opened at olf normal contacts 145.

At the semi-automatic operators position, a signal (not shown) is operated upon the hanging u of the receiver at the calling substation. e operator, nal, initiates the release of the equipment in the machine switching oliice in any well known or desired manner.

It is thought that from the foregoin description and from an inspection o? the rawings, including the tables shown in Figs. 5 and 6, it will be readily understood how any four digit number set up on the operators ke s may be transmitted to the alltomati otlibe, decoded, and transmitted to the automatic switches.

Referrin now particularly to Fig. 4, the function o certain supervisory equipment associated with the sender S and sequence switch SE will be explained. It sometimes happens that a contact becomes dirty, therey preventing the associated circuits from functioning properly. In most cases a dirt contact stops the decoder or gives an indlcation that can be detected, regardless of the number called, and is therefore, easily noticeable upon inspection. However, in case a contact on one of the relays 304-315, inclusive, becomes dirty, it is not so easily detected for the reason that the decoder functions apparently as well as ever, but sends out the wrong number occasionally. In order to detect dirty contacts on the set up relays 304-315, inclusive, the sender S is provided with an extra wiper 329 and associated bank, and also relays 361-362and the associated equipment have been provided.

It will be remembered that stop relay 326 is in a deenergized condition and that rela 323 is energized during the time that the sender is operating to control the automatic switches. It will be remembered also that stop relay 326 energizes and terminates each git being sent out by the sender, in response to the energization of test relay 327,

upon noting thls sigwhich relay is energized through one or more of the contacts on the set up relays, Fig. 3. Ordinarily, stop relay 326 energizes in respouse to the energization of test rela 327 before the wi rs of the sender reac the twelfth set o bank contacts. Assuming however, that one of the Acontacts on one o the set u relays is dirty and that a number is cal ed which brings such contact into play, test relay 327 is not,energzed at the pro r time owing to the circuit being open at t e dirty contact. As a result, stop relay 326 is still deenergized when the sender arrives on the twelfth set of bank contacts.

With the sender wipers on the twelfth set of bank contacts under these conditions, a circuit is closed for the upper winding of relay 362 as follows: From ground by way of resting contact of armature 355 and said armature, working contact of armature 346 and said armature, wiper 329, the twelfth associated bank contact, and the upper winding of relay 362 to battery. Relay 362, upon energizing, closes at armature 373 a locking circuit for its lower winding through lamp 372, key contacts 370, and relay 361. As a further result of the energization of relay 362, it disconnects sending relay 324 from ground at armature 374; closes a multiple circuit for relay 365 at armature 375; places a multiple ground on conductor 202 at armature 376 so as to hold up the set of set up relays that has been operated in order to enable an attendant to discover the open contact easily; and at armature 377 places ground on the 'unction of relay 321 and resistance 381, there y causing the trunk which is connected to decoder at this time to switch through to the associated selector and become disconnected from the decoder in the hereinbefore described manner.

In this case it will be noted that, altho the trunk is disconnected from the decoder, the

sender S and sequence switch SE are not restored to normal as is the case when the call goes through successfully,y but are left in their respective positions in which they were when the trouble manifested itself.

It may be pointed out that the decoder is guarded against seizure when relay 271, Fig. 3, falls back after the trunk has been disconnected from the decoder, the circuit being as follows: From ground by way of the grounded conductor 202 (which conductor is grounded at armature 376 of relay 362, Fig. 4,) working contact of armature 241 of relay 230, Fig. 3, and said armature, conductor 201, and armature 274 and its resting contact to conductor 127.

As a result of the closing of the locking circuit of the lower winding of the relay 373, the individual lamp 372 becomes lighted and the common relay 361 energizes. Upon energizing, relay 361 places ground on the conductor 377 whereupon an alarm (not shown) yassociated with conductor 377 is operated.

The attendant, ma now locate the decoder by means of the lig ted lamp 372, and, u n noting the position of the se uence switch gg, may ascertain the set of re a s from which the trouble is comin After aving located and cleared the trou le, the attendant opens the key contacts 370 whereupon relays 361 and 362 deener ize; the lamp 37 2 becomes extinguished an the ground is removed from the alarm conductor 377. As a result of the deener 'zation of relay 362, it removes groun from locking conductor 202 at armature 376, whereupon the decoder is rendered idle and the locked u relays of the decoder deenergize. As a sti l further result of its deenergization relay 362, opens the circuit of relay 365 at armature 375, whereupon relay 365 deenergizes and the sender S and the sequence switch SE are restored to normal in the hereinbefore described manner.

It will be understood that this disclosure is merel typical of the applicants invention, an that its use is not limited to decoding devices in automatic tele hone systems or even in telephone systems roadly.

What is claimed 1s:

1. In a telephone system comprising a machine switching oiiice, a manual call indicator olce, and a step by step oce, code sending apparatus in the machine switching olce for setting the call indicators in the manual oliice, and translating equipment responsive to said sending equipment vfor operating the switches in the step by step oiiice.

2. In a tele hone system, apparatus for receiving code number impulses and for operating switches on a decimal basis responsive thereto, said apparatus comprising sets of decoding relays, one set per digit, a sending switch for transmitting decimal impulses, and a sequence switch for placing said sending switch under the control of said relay sets in succession.

r3. In a telephone system, a paratus for receiving coded number impu ses of different polarity and for operating switches on a decimal basis responsive thereto, said apparatus comprising a common `set of receiving relays sensitive to the code impulses, a plurality of sets of decoding relays controlled by said receiving relays, a sending switch for transmitting impulses on a decimal basis, and a sequence switch for placing said sending switch under the control of said decoding relay sets in succession.

4. The combination, with a registering device adapted to be set in accordance with a d igit in a called number, of a sending switch for transmitting impulses under control of said device, a stop wiper for said switch, circuit connections whereby said device places ground potentials on certain contacts eny gaged by said wiper and battery potentials on certain other of said contacts, a stop relay controlled by said stop wiper, and means intervening between said relay and wi er for enabling the former to respond to either a battery or a ground potential at the proper time.

5. In a register sender, sending mechanism including a counting switch for determining the number of impulses in the digits transmitted, a register for controlling said switch, conductors less in number than the maximum number of impulses to be counted, and means whereby said register controls said switch over any one of said conductors.

6. In a register sender, sending mechanism includingr a counting switch', a relay for stopping the transmission of impulses, circuits for energizing said relay in any one of a plurality of positions of said switch, means including a register for preparing any desired one of said circuits, and conductors less in number than said circuits over which the same are completed.

7. In a register sender, sending mechanism including a counting switch, a relay for stopping they transmission of impulses, circuits for energizing said relay in any one of a plurality of positions ofesaid switch, means including a register for preparing any desired one of said circuits two conductors each common to one half of said circuits, and a plurality of other conductors each common to two of said circuits.

8. In a register sender, sending mechanism including a counting switch, a register for controlling said counting switch but normally ineffective, means for starting said counting switch and for operating the same independent of register control, and means responsive to a full operation of said counting switch for placing the same under the control of said register.

9. In a register sender, sending mechanism including a counting switch, means for automatically operating and reoperating said switch, a register, means responsive to the first operation of said switch for placing the same under control of said register during the second operation, and impulse sending mechanism controlled by said switch during the second operation but not during the iirst.

10. In a register sender, relays responsive to code impulses of different character, registers successively set by said relays, a two conductor control circuit, sending mechanism for transmitting impulses over the two conductors of said circuit in series, and means m for controlling said sending mechanism in v accordance with the scttlng of said reglsters.

11. In a register sender, relays responsive to code impulses of different character, registers successively set by said relays, a control circuit, sending mechanism for transmitting impulses over said control circuit by producions therein, and means for controlling sai sending mechanism in accordance with the setting of said registers. 12. In a telephone s stem, a trunk line comprising Vtwo norma y disconnected sections, the second of which terminates in an automatic switch, a register sender, a hunting switch for associating said trunk line with said register sender, an impulse receiving relay in said register sender, means for connecting said relay to a conductor of the first section of said trunk line through a wiper of said hunting switch, an impulse transmitting rela in said register sender, and a control circuit for said automatic switch including a conductor of the second section, another wiper of said hunting switch, and contacts on said last mentioned relay.

13. In a telephone-system, a trunk line comprising two normally disconnected sections, the second of which terminates in an automatic switch, a register sender, a hunting switch for associating said trunk lines with said register sender, impulse transmitting and impulse receiving relays in said register sender, a circuit for the impulse receiving relay including wipers of said hunting switch and the two sides of the first section of said trunk line in series, a line relay in said automatic switch, and a circuit for said line relay including the two sides of the second section in series, other wipers of said hunting switch, and contacts of said transmitting relay.

14. In a telephone system, a trunk line comprising two normally disconnected sections, the second of which terminates in an automatic switch, a register sender, a hunting switch for associating said trunk line with said register sender, impulse transmitting and impulse receiving relays in said register sender, a circuit for the impulse receiving relay including wipers of said hunting switch and the two sides of the first section of said trunk line in series, a line relay in said automatic switch, a circuit for said line relay including the two sides of the second section in series, other wi ers of said hunting switch, and contacts o said transmitting relay, andV means entirely outside said register sender for supplying current to said circuits.

15. In a telephone system, a trunk line comprising two normally disconnected sections, the second of which terminates in an automatic switch, a register sender, a hunting switch for associating said trunk line with said register sender, means for extending the first and second sections separately through wipers of said hunting switch to said register sender, means in said register sender for receiving a digit transmitted by a particular system of impulses over the first section, and means in said register sender for retransmitting the same digit to said autoing series of interrup llA -matic switch over the second section by means of a different system of impulses.

16. In a telephone system, a trunk line comprisingr two normally disconnected sections, the second of which terminates in an automatic switch, a register sender, a hunting switch for associating said trunk line with said register sender, means for extending the first and second sections separately through wipers of said hunting switch to said register sender, means in said register sender for receiving a digit transmitted by code impulses over the rst section, and means in said register senderfor retransmitting the same digit to said automatic switch by means of declmal impulses passing over the two sides of the second section in series.

17. In a telephone system, a trunk line, a register sender, a switch for connecting the trunk line with said register sender, a line relay for operating said switch controlled over said trunk line, a relay iny said register sender, a switching relay in said trunk line for disconnecting said line relay from the trunk line, an energizing circuit including the said switching relay and the register sender relay in series, and a holding circuit for said switch controlled by said register sender relay.

18. In a telephone system, a trunk line divided into two sections, a call director, a relay and a circuit for energizin it to connect both sections of said trunk ine to said director over separate paths, a second relay and a circuit for subsequently energizing it,

means for deenergizing the first named relay after the energization of the second relay to disconnect said sections from said call director, and normally closed contacts on the first named relay and normally open contacts on the other relay for connecting the two sections together.

19. In a telephone system, a trunk line, a register, a switch for associating said trunk line with said register, a holding circuit for said switch closed in said register, a timin device for opening said holding circuit, an means controlled by said register in response to impulses received over said trunk line for closling said holding circuit over another at i. p 20. In a telephone system, a trunk line, a register, a switch for associating said trunk line with said register, a timing device and means for starting it responsive to the association of the trunk line with the register, means for setting the register responsive to impulses received over the trunk line, and a holding circuit for said switch controlled jointly by the register and said timing device. 21. In a telephone system, a trunk line, a register, a switch for connecting the two together, a holding conductor, means for establishing a current How over said conductor to hold the connection, a timing device for stopping the current flow over said conductor, means for operating said register over said trunk line to register a number, and means controlled by said register upon its operation for preventing the stopping of the current flow over said conductor y said timing device.

22. In a telephone system, a trunk line, a register, a switch for connectin said register to said trunk line, means contro ed over said trunk line for settin said register, and a timing device for reeasing said switch in case said register is not set before said` device operates.

23. In combination, a plurality of conductors, means for placing a distinctlve potential on any one of said conductors, means for testing all said conductors successively regardless of which one of them has the distinctive potential on it, an alarm device, means effective after all of said conductors have been tested for operating said alarm device, and means for preventln said alarm device from operating in case said distinctive potential was found on one of said conductors.

24. In combination, a multiosition testing device, conductors associate respectively, with a plurality of said positions, a test relay, means for preparing an operating circuit for said test relay over any one of said conductors, means for bringing said device into its several positions successlvely to complete said circuit, an alarm device, means for o erating said alarm device responsive to said testing device arriving in a. position beyond the positions associated with said conductors, and means for preventing the said operation of said alarm device in case said test relay has been operated.

25. In an impulse sender employing a multi-position testingdevice operatingsimultaneously with the sending of impulses and operative to stop the transmission of impulses at a variable point, an alarm device, and means for operating said device in case said testing device has not functioned when a predetermined position is reached.

26. In combination, group conductors and individual'conductors, means for registering a digit by rendering alive one group conductor and one individual conductor, and means for determining the digit registered by determining the group conductor and the individual conductor rendered alive.

27 In combination', group conductors each corresponding to a separate plurality of di its, individual conductors each corres ning to only one digit in any group of igits to which a group conductor corresponds, and means for registering a digit by rendering alive the group conductor corresponding to the group kof digits within which the said.

digit is located and by rendering alive the individual conductor that corresponds to the counted.

said digit within the group of digitsassigned tothe live group conductor.

28. In a controlling device for controlling the extent of movement of an automatic switch, a plurality of test conductors, means for advancing said controlling device in synchronism with said automatic switch to test said conductors a plurality of times, and registering means for predetermining over which of said conductors the test shall be effective and for determining during which of the testing operations the said test shall be successfu 29. In a register sendery including a relay 'storage device, a first plurality of conductors,

a second pluralit of conductors, means including part of said relays for rendering alive any conductor of said first plurality, means including the remaining relays for rendering alive any conductor of the second plurality, and a counting device controlled over the live conductors.

30. A register sender as claimed inv claim 29 in which the counting device is a progres- `sively movable switch having a contact bank 32. In a register sender, a registering device and a counting device controlled thereby, and testing conductors directly connecting two devices which are a sub-multiple of -the value of the largest digit to be counted.

33. In a relay storage device, a plurality of group test conductors and 'a plurality of individual test conductors, and contacts on the relays of said device operated in accordance with a registered digit for joining the group conductor corresponding to such digit to the individual test conductor corresponding to the said digit.

34. The combination in a storage device for storing digits, comprising four relays, two group test conductors, live individual test conductors, an interconnecting conductor, contacts on one relay for connecting one end .of the interconnecting conductor with either group test conductor, and contacts cn the other relays for connecting the other end of the interconnecting conductor with any one ofthe individual test conductors.

35. In combination, an impulse sender for transmitting variable series of digit impulses, conductors less in number than the maximum number of possible values that any digit may have, and means controlled over an one of said conductors for fixing the value o a transmitted digit in accordance with the conductor over which the control is exercised.

36. In combination, an impulse sender for transmitting variable series of digit impulses,

conductors less in number than the maximum number of possible values that any digit may have, means for exercising a control over any one of said conductors, said control being of either of two characters, and means responsive to said control for fixing the value of a transmitted digit in accordance with the conductor over which the control is exercised and in accordance with the character of the exercised control.

37. In combination, a multi-position testing device having a plurality of test positions and an ala-rm position, means for driving said device through its test positions and into its alarm position, an alarm device, and means for operating said alarm device or not depending upon test conditions encountered b said device while it is being driven throug its test positions.

38. In a telephone system, a selective switch, a trunk incoming to said switch and accessible to an operator, a plurality of register senders, a sender selector for connecting said trunk to any of said senders, an operators position, means controlled by the operator for sending code impulses from her position through the sender selector to set the connected sender, and means controlled by said sender for selectively operating said selective switch.

39. In a telephone system, a selective switch, a trunk incoming to said switch and used exclusively by yoperators in extending connectionsv thereto, a plurality of register senders, a sender selector for connecting said trunk to any of said senders, an operators position, means controlled by the operator for sending code impulses from her position through the sender selector to set the connected sender, and means controlled by said sender for selectively operating said selective switch.

40. In combination, means for transmitt-ing a plurality of series of impulses, and means associated therewith and effective only in case a given series is not correctly transmitted for preventing the transmission of the remaining series of impulses.

41. In combination, an impulse sender arranged to transmit a predetermined plurality of series of impulses, means for predetermining the respective values of the said series of impulses, and means for preventing the transmission of the remaining series of impulses in case a given series is not correctly transmitted.

42. In an impulse sender, means for transmitting a plurality of series of impulses, and means for preventing the transmission of the lll remaining series of impulses in case a given IIC series comprises a predetermined number of impulses.

43. In an impulse sender, means for transmitting a plurality of series of impulses, and means for preventing the transmission of the remaining series of impulses in case a given series comprises more than a predetermined number of impulses.

44. In a sender for transmitting impulses corresponding to registered digits, a plurality of wipers and assoclated banks, a plurality of control conductors terminating in said banks, test circuits including said plurality of wipers and associated banks and a pair of said control conductors in series, means for successively testing over different pairs of said control conductors, and means for terminating the transmission of impulses responsive to the completion of one of said test circuits over a pair of said control conductors.

45. In a register sender, a plurality of registers, each comprising a plurality of registering devices, means for setting the registering devices of each register in combinations to record digits, each device having sender control contacts, a sender controlled directly through the sender control contacts of the first register, and means operable after the sender has been controlled by said first register for transferring the control of said sender from said first register control contacts to said second register control contacts.

46. In a register sender, a plurality of registers each comprising a plurality of registering devices, means for setting the registering devices of each register in combinations to store digits, sender control contacts associated with each of said registering devices, a sender controlled directly through the sender control contacts of the first register to transmit the digits stored thereon, a plurality of transferring devices, said transferring devices being operable to transfer the control of the sender from the sender control contacts of the first register to the sender control contacts of each of the remaining registers successively.

47. In a register sender comprising a rotary switch having two wipers and arranged to ltransmit an impulse each time the wipers are advanced one step, a set of bank contacts for each of said wipers, means for placing a marking on certain bank contacts of eachset, and means effective when said wipers simultaneously engage marked bank contacts for stopping the transmission of impulses.

48. In combination, a counting switch having a plurality of Wipers and a set of bank contacts associated with each wiper, means for marking certain bank contacts in each set, means for operating said counting switch, and means responsive to the operation of said switch for transmitting a single series of impulses whose length is governed by the marklng on said bank contacts.

49. In an automatic telephone system using register translators any one of which may be connected to a trunk line over which a connection is to be set up, a combined testing and holding conductor in the connection set up between a register translator and a trunk line, there being a current flow over said conductor while the connection exists between the trunk line and register translator, means in the register` rtranslator forstopping the current flow over said conductor, and means responsive to the cessation 'of current flow for severing the connection between thetrunk line and the re ister translator.

50. In a te ephone system lwherein connections are set up over trunk lines and wherein an auxiliar device is temporarily connected under t e control of a testing device to a trunk line over which a connection is to be set up, a combined testing and holding conductor included in the connection, said testing operation being carried out over said conductor, there being a holding current flowing over said conductor while the connection exists, means in the auxiliary device for stopping the current flow over said holding conductor, and means responsive thereto for severing the connection between such device and the trunk line. Y

51. In a signalling system, a register sender having a si nal 11ne incoming thereto, groups of code-digit storage relays, means at the distant end of said line for transmitting signals in code over said line to the receiver, means for associating said storage-relay groups with said line successively whereby the coded signals are received and effectively stored on'said relay groups, respectively, electro-responsive devices, an impulse sender, and means for operating said impulse sender under the control of said relay groups, said impulse sender being effective when operated to transmit series of impulses to said electroresponsive devices depending respectively upon the signals stored in said relay storage groups.

52. In combination, means for transmitting combinations of impulses representing the digits of a number in code, storage relay groups each having a separate relay for each element cf the code, means for rendering said storage-relay groups effective successively to receive the coded digits, impulse sending apparatus, electro-responsive devices, and means for operating said sending apparatus to transmit a series of uncoded digit impulses to each of said electro-responsive devices under the control of said relay groups respectively.

53. In a signalling system, a receiver arranged to receive digits transmitted thereto in code, there being a group of signal channels ion incoming thereto, digit-storage relay groups ber of impulses dependent upon the digit in said receiver each containing Stora relays stored o n thc storage device.

corresponding, respective1y,to saidc annels, In witness whereof, I hereunto subscrlbe means for associating said channels with said my llame thlS 19th day 0f Septelllbel, A- 1)-,

5 storage-relay groups in succession while digit 1922. 4) signals are being received, whereby successive ARTHUR J. RAY. digit-signal combinations are stored on said storage relay groups, respectively, electro-responsive devices corresponding, respectively,

to said storage-relay groups, and a digit-im- 'I5 pulse sender operable under control of each storage-relay group to send a variable series of impulses to the correspondin electro-responsive device whereby the device takes up a setting dependent u on the digit value S0 stored on the correspon mg relay group.

54. In a signalling system, a receiver arranged/to receive digits transmitted thereto in accordance with a-multi-unit code, digit- 2 storage relay groups in said receiver each con- 85 taining storage relays correspondingrespectively to the units of the code, means for rendering said storage relays effective to operate and store received digits, electro-responsive devices corresponding respectively 90,

to said storage-relay groups, anda digit-impulse sender operable under the control of 'each storage relay group to send a variable series of impulses to the correspondingr electro-responsive device whereby the device 9 takes up a setting dependent upon the value of the digit stored on the corresponding relay group.

55. In a signalling system, a receiver ar:` ranged to receive digits transmitted thereto in code, there being a group of signal channels incoming thereto corresponding, respectively, to the units of the code, digit-storage 40 relay groups in each receiver containing stor- 195 age relays corresponding, respectively, to said channels, means for associating said channels with said storage-relay groups in succession while digit signals are being re- .Ceived, whereby successive digit-signal com- 110 binations are stored on said storage-relay A groups, respectively, a digit-impulse sender, and means for operating said digit-impulse sender under the control of each storage-relay group tosend a variable series of impulses of nb a number dependent upon the digit value stored on the corresponding relay group.

56. In a signalling system, a receiver ar- 5 ranged to receive digits transmitted thereto i n accordance with a multi-unit code, a group of signal channels incoming to said receiver and corresponding respectively to the units of said code, digit-storage devices, means for a0 associating said devices in succession with 125 said channels while digit signals are being received whereby the successive digits are stored on said storage devices respectively, and a digit-impulse sender operable under control of each storage device to send a num- 139 

